CANopen 块传输通信详解

1.块上传详解(读取)

 

这里以图2为例子， 进行说明

假设主节点为01，待读取节点为0x1b

读取的数据是

UNS8 g_upgrade_buf_appbin[258]="bbbcccddd111222333444555666777888999AAA\0";

/* Mapped at index 0x2007, subindex 0x01 */

 

1).主节点：发送读取数据初始化

发送：

A0 07 20 01 10 00 00 00

data[0] = (5 << 5) | SDO_BCS_INITIATE_UPLOAD_REQUEST;

data[1] = index & 0xFF;        /* LSB */

data[2] = (index >> 8) & 0xFF; /* MSB */

data[3] = subIndex;

data[4] = SDO_BLOCK_SIZE;

for (i = 5 ; i < 8 ; i++)

data[i] = 0;

 

2).从节点：服务器端响应”需要读取的总数据包字节数” 

接收：

C2  07 20 01 27 00 00 00

data[0] = (6 << 5) | (1 << 1) | SDO_BSS_INITIATE_UPLOAD_RESPONSE;

data[1] = index & 0xFF;        /* LSB */

data[2] = (index >> 8) & 0xFF; /* MSB */

data[3] = subIndex;

data[4] = (UNS8) nbBytes;

data[5] = (UNS8) (nbBytes >> 8);

data[6] = (UNS8) (nbBytes >> 16);

data[7] = (UNS8) (nbBytes >> 24);

 

3).主节点：收到响应后，发送命令，表示可以开始传输了

发送：

A3 00 00 00  00 00 00 00

data[0] = (5 << 5) | SDO_BCS_START_UPLOAD;

for (i = 1 ; i < 8 ; i++)

data[i] = 0;

 

4).从节点：开始循环向主节点发送数据包

接收：

01 62 62 62 63 63 63 64

02 64 64 31 31 31 32 32

03 32 33 33 33 34 34 34

04 35 35 35 36 36 36 37

05 37 37 38 38 38 39 39

86 39 41 41 41 00 00 00

data[0] = SeqNo;

err = lineToSDO(d, line, 7, data + 1);

 

5).主节点：告诉从节点，我收到了多少条包！

发送：

A2 06 10 00  00 00 00 00 

data[0] = (5 << 5) | SDO_BCS_UPLOAD_RESPONSE;

data[1] = d->transfers[line].seqno;

data[2] = SDO_BLOCK_SIZE;

data[3] = data[4] = data[5] = data[6] = data[7] = 0;

 

6).从节点：告诉主节点，已经发送完毕

接收：

Cd 00 00 00 00 00 00 00

data[0] = (6 << 5) | ((d->transfers[line].endfield) << 2)|SDO_BCS_END_DOWNLOAD_REQUEST;

for (i = 1 ; i < 8 ; i++)

data[i] = 0;

 

7).主节点：告诉从节点，我也接收完毕了，整个传输完成!

发送：

A1 00 00 00  00 00 00 00

data[0] = (5 << 5) | SDO_BCS_END_UPLOAD_REQUEST;

for (i = 1 ; i < 8 ; i++)

data[i] = 0;

 

2.块下载详解（写入）

 

图3

这里以图3为例子， 进行说明

假设主节点为01，待写入节点为0x1b

假如待写入的数据是

UUNS8 write_net_block_buf[] =  "0123456789aaabbbcccddd\0";

/* Mapped at index 0x2007, subindex 0x01 */

 

1).主节点：告诉从节点我要写入多少个字节数

发送：

C2 07 20 01 18 00 00 00

buf[0] = (6 << 5) | (1 << 1 );   /* CCS = 6 , CC = 0 , S = 1 , CS = 0 */

buf[1] = index & 0xFF;        /* LSB */

buf[2] = (index >> 8) & 0xFF; /* MSB */

buf[3] = subIndex;

for (i = 0 ; i < 4 ; i++)

buf[i+4] = (UNS8)((count >> (i<<3))); /* i*8 */

 

2).从节点：我准备好了，可以写入数据

接收：

A0 07 20 01 10 00 00 00

data[0] = (5 << 5) | SDO_BSS_INITIATE_DOWNLOAD_RESPONSE;

data[1] = (UNS8) index;        /* LSB */

data[2] = (UNS8) (index >> 8); /* MSB */

data[3] = subIndex;

data[4] = SDO_BLOCK_SIZE;

data[5] = data[6] = data[7] = 0;

 

3).主节点：收到响应后，开始逐条发送数据，无需响应

发送：

01 30 31 32 33 34 35 36

02 37 38 39 61 61 61 62

03 62 62 63 63 63 64 65

84 64 00 00 00 00 00 00

当实际发送字节大于7个字节时：

data[0] = SeqNo;

err = lineToSDO(d, line, 7, data + 1);

剩余的小于7个字节的发送时：

data[0] = 0x80 | SeqNo;

err = lineToSDO(d, line, nbBytes, data + 1); //实际的剩余字节

for (i = nbBytes + 1 ; i < 8 ; i++) //多余的空间填0

 data[i] = 0;

 

4).从节点：告诉主节点我收到了多少条

接收：

A2 04 10 00 00 00 00 00

data[0] = (5 << 5) | SDO_BSS_DOWNLOAD_RESPONSE;

data[1] = d->transfers[line].seqno;

data[2] = SDO_BLOCK_SIZE;

data[3] = data[4] = data[5] = data[6] = data[7] = 0;

 

5).主节点：告诉从节点，写入完毕！

发送：

D1 00 00 00  00 00 00 00

data[0] = (6 << 5) | ((d->transfers[line].endfield) << 2) | SDO_BCS_END_DOWNLOAD_REQUEST;

for (i = 1 ; i < 8 ; i++)

data[i] = 0;

 

6).从节点：告诉主节点，我知道写入完毕了

将传输结构体里面的数据拷贝到数据字典里，并复位SDO传输!

接收：

A1 00 00 00 00 00 00 00

data[0] = (5 << 5) | SDO_BSS_END_DOWNLOAD_RESPONSE;

for (i = 1 ; i < 8 ; i++)

data[i] = 0;